A few weeks ago, I picked up a 1994 Korean Squier Strat serial number NK4XXX - when I peeked inside, I found the neck and brdige pickups were not stock.
I was able to get an ID on the neck that I think is correct (Seymour Duncan STK-S1 stacked four wire)
Not having any luck with the middle - it might be a Dimarzio (that's on the pup cover) but their tech support can't say for sure without having me send it to them - not gonna happen!
They said it might be a "an old version of a vintage Strat pickup called VS-1"
I think the VS-1 was also known as a DP-108.
The DC resistance is about 5.5K ohms
Some picures are here:
http://s1092.photobucket.com/albums/i418/hudsonnh/Middle%20Pickup/Anyone ever seen an old Dimarzio like this and have any clues?